Preserve fast-math flags after reassociation and commutation. Update test cases
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174571 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/InstCombine/InstructionCombining.cpp b/lib/Transforms/InstCombine/InstructionCombining.cpp
index dc7fe5c..c6115e3 100644
--- a/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -162,6 +162,21 @@
return !Overflow;
}
+/// Conservatively clears subclassOptionalData after a reassociation or
+/// commutation. We preserve fast-math flags when applicable as they can be
+/// preserved.
+static void ClearSubclassDataAfterReassociation(BinaryOperator &I) {
+ FPMathOperator *FPMO = dyn_cast<FPMathOperator>(&I);
+ if (!FPMO) {
+ I.clearSubclassOptionalData();
+ return;
+ }
+
+ FastMathFlags FMF = I.getFastMathFlags();
+ I.clearSubclassOptionalData();
+ I.setFastMathFlags(FMF);
+}
+
/// SimplifyAssociativeOrCommutative - This performs a few simplifications for
/// operators which are associative or commutative:
//
@@ -219,7 +234,7 @@
I.clearSubclassOptionalData();
I.setHasNoSignedWrap(true);
} else {
- I.clearSubclassOptionalData();
+ ClearSubclassDataAfterReassociation(I);
}
Changed = true;
@@ -241,7 +256,7 @@
I.setOperand(1, C);
// Conservatively clear the optional flags, since they may not be
// preserved by the reassociation.
- I.clearSubclassOptionalData();
+ ClearSubclassDataAfterReassociation(I);
Changed = true;
++NumReassoc;
continue;
@@ -263,7 +278,7 @@
I.setOperand(1, B);
// Conservatively clear the optional flags, since they may not be
// preserved by the reassociation.
- I.clearSubclassOptionalData();
+ ClearSubclassDataAfterReassociation(I);
Changed = true;
++NumReassoc;
continue;
@@ -283,7 +298,7 @@
I.setOperand(1, V);
// Conservatively clear the optional flags, since they may not be
// preserved by the reassociation.
- I.clearSubclassOptionalData();
+ ClearSubclassDataAfterReassociation(I);
Changed = true;
++NumReassoc;
continue;
@@ -310,7 +325,7 @@
I.setOperand(1, Folded);
// Conservatively clear the optional flags, since they may not be
// preserved by the reassociation.
- I.clearSubclassOptionalData();
+ ClearSubclassDataAfterReassociation(I);
Changed = true;
continue;